Q: A prescription calls for the dispensing of a 4% Pilocar solution with the directions of "gtti au TID." How many mg of pilocarpine hydrochloride is being used per day? Assume that the dropper is calibrated to deliver 20 drops to the mL.
Explanation: The patient is placing 1 drop in each eye three times a day, thus a total of 6 drops. This equates to 0.3 mL since the dropper calibra- tion was 20 drops to a mL. 20 drops _6 drops 1 mL - xmL x=0.3 mL Since a 4% Pilocar solution contains 4000 mg of drug per 100 mL. 4000mg _ ~ 100 mL - 0.3 mL x= 12mg
Q: The pharmacokinetic parameter known as clearance is essentially the
Explanation: This is the definition of total systemic (whole body) clearance, which is the sum of all the separate clearances (ie, renal, hepatic,etc).
Q: The primary advantage of oxaprozin over lost other nonsteroidal anti-inflammatory drugs (NSAIDs) is that it
Explanation: Although the NSAIDs are structurally different, they all possess similar pharmacological properties and all inhibit prostaglandin synthesis. Furthermore, these drugs produce similar adverse effects, including gastrointestinal (GI) intolerance. Oxaprozin (Daypro) has the longest half-life of the group (approximately 42 to 50 hours) and is recommended to be given on a once-a-day basis.
Q: Ibuprofen has a pKa of 5.5. If the pH of a patient's urine is 7.5, what would be the ratio of dissociated to undissociated drug?
Explanation: For determining the ratio of a weak acid to its salt present at a given pH, the Henderson-Hasselbalch equation is used. [disassociated] pH =pKa + log [undisassociated] If the values for pH and pKa are used in this equation, it can be seen that the ratio of the dissociated form of the drug to the undissociated form will be the antilog of 2, a numeric value of 100. B 7.5 =5.5 + log A B log A =+2 B A=100
Q: Which of the following therapeutic agents is specifically contraindicated for use in patients who have bronchial asthma?
Explanation: Sotalol (Betapace) is used primarily for its ability to block beta-adrenergic activity, and is therefore useful in treating patients suffering from ventricular arrhythmias. How- ever, because beta-adrenergic blockade also tends to increase airway resistance, the drug is usually contraindicated for use in patients suffering from asthma or severe allergies.